Due to the attack, some admins logged out everyone’s account for security. This also means you’d be logged out of third-party apps, but the apps may not respond properly.
You can try to log out of the account on the third party app and relogin, see if that fixes the issue
In my experience, no, especially outside of the US.
In many places/countries, there are more android than iphone users. This is especially true in developing countries, but also some developed ones too. It’s not uncommon for everyone in these areas to use alternative messaging platform like whatsapp, telegram, or line, so there was barely any difference between android and iphone.
So it’s barely a deal-breaker, at least, in this scenario.
If you autopost the content manually, then technically you can be considered not a bot.
Personally, though, I think having different account for bot related stuff seems like a good idea.